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<a name="g_t_005fgfortran_005fcaf_005fco_005fmax-_002d_002d_002d-Collective-maximum-reduction"></a>
<h4 class="subsection">7.2.33 <code>_gfortran_caf_co_max</code> &mdash; Collective maximum reduction</h4>
<a name="index-Coarray_002c-_005fgfortran_005fcaf_005fco_005fmax"></a>

<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Calculates for each array element of the variable <var>a</var> the maximum
value for that element in the current team; if <var>result_image</var> has the
value 0, the result shall be stored on all images, otherwise, only on the
specified image. This function operates on numeric values and character
strings.
</p>
</dd>
<dt><em>Syntax</em>:</dt>
<dd><p><code>void _gfortran_caf_co_max (gfc_descriptor_t *a, int result_image,
int *stat, char *errmsg, int a_len, size_t errmsg_len)</code>
</p>
</dd>
<dt><em>Arguments</em>:</dt>
<dd><table>
<tr><td width="15%"><var>a</var></td><td width="70%">intent(inout)  An array descriptor for the data to be
processed.  On the destination image(s) the result overwrites the old content.</td></tr>
<tr><td width="15%"><var>result_image</var></td><td width="70%">intent(in)  The ID of the image to which the
reduced value should be copied to; if zero, it has to be copied to all images.</td></tr>
<tr><td width="15%"><var>stat</var></td><td width="70%">intent(out)  Stores the status STAT= and may be NULL.</td></tr>
<tr><td width="15%"><var>errmsg</var></td><td width="70%">intent(out)  When an error occurs, this will be set to
an error message; may be NULL.</td></tr>
<tr><td width="15%"><var>a_len</var></td><td width="70%">intent(in)  the string length of argument <var>a</var></td></tr>
<tr><td width="15%"><var>errmsg_len</var></td><td width="70%">intent(in)  the buffer size of errmsg</td></tr>
</table>

</dd>
<dt><em>NOTES</em></dt>
<dd><p>If <var>result_image</var> is nonzero, the data in the array descriptor <var>a</var> on
all images except of the specified one become undefined; hence, the library may
make use of this.
</p></dd>
</dl>






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